And for PC if you get a pop up your game is interrupted. You can't talk to friends in game unless you had some kind of third party service which doesn't work that well.
Steam. It's like Xbox Live for the PC, right down to parties.
If you want mics you need a stuffty third party team speak line.
Or ventrilo, or steam chat, or in-game chat, all of which are capable of providing hifi audio that can't be achieved with the xbox live voice codex.
You need to port forward just for online play. There is so many other issues that make the PC un-convenient.
Only when you're hosting a server for some games, but it only takes like 2 minutes and then you're set for life.
Why would you pay 2,700+ for World of Warcraft?
Ha ha no, that was my arena rating. I was in the top-ten for warriors in my battlegroup for three seasons.